Abstract
By immersing in a chloride salt bath with added chromium powder at temperatures lower than 873K for 1-4hours, chromium carbonitride coatings thick enough for practical application were formed on various pre-nitrided steels. Wear- and seizure- resistance of steel coated by this method was superior to those of hardened steel and nitrided steel, and comparable to those of steels coated by PVD and high temperature TRD, CVD. Oxidation resistance improvement by this method was close to that of chromium carbide coated steel by high temperature TRD. However, toughness of steel thus coated was inferior to that of hardened steel. The coating was concluded to be applicable to aluminum die casting and aluminum extrusion dies.
